Wood stain



Patented- Oct. 16, 1934 PATENT, oFF'no woon STAIN Charles G. Moore,Lakewood, and Milton Zucker, Cleveland, Ohio, a'ssignors to The Glidden"Company, Cleveland, Ohio, a corporation of I Ohio No Drawing.

. 1 Claim.

In the old varnish system of wood finishing, the

staining of the wood was a relatively simple matter. Benzol-soluble dyes(which can be made sufliciently light-resistant for furniture work andthe like) were mixed to the desired shade, and

of solvents came into use, including alcohols,

applied. These readily dried, and the pores of the wood were then filledwith a filler composition 'consisting of pigment mixed with oil, drierand 'contained aliphatic hydrocarbons or turpentine.

In no case was a solvent for the dye present in the top coats, and thedye thus remained in the wood and no trouble was encountered. With theadvent of wood lacquers however, a new series esters and the aromatichydrocarbons, benzol, toluol and xylol. The use of such lacquers overthe old type of stains was found to result in some of the dye leavingthe wood and going into solueffects. In mixed color stains, the dyesoften tended to bleed unevenly into the lacquer coating, therebyresulting in a change of color; and

the acid in the benzol dyes often rotted the lacquer film, destroyingits toughness and adhesion.

Water-soluble acid dyes, which had been used to a limited extent on veryhigh grade varnish work were next brought into use in this connection.These colors (of the diazo type for the greatest part) have a relativelygood resistance to the .action of light, and do not tend to bleed intothe lacquer film. .These stains however, have a very seriousdisadvantage, which has prevented their more general use. When water oran aqueous solution is applied to wood, it is absorbed and the fiber ofthe wood is raised. For the filling operation, which follows thestaining, unless the wood is perfectly smooth, the filler does not wipeoff well and gray marks-are left in the uneven portions of the woodwhere pigment has covered the stain. The fibers raised by the water musttherefore be sanded down. In order to do this properly, a wash coat ofshellac (about one-half .pound per gallon of alcohol) must be applied.This stiffens. the wood fibers so that the sandpaper will cut themeasily'and evenly; but it can be readily seen that this extrashellacking and sanding requires such labor and time that water .fi

soluble stains have not been used to much extent In accordance with ourpresent invention, the

desirable features of water soluble stains how- Application Ootober a1,1529, Serial No. 403,909

ever may be made available without objectionably raising'the fiber of.the wood, and at the same time an organic type of solvent may be emdrousor which have a small water content have a general advantage also inthat since their preparation doesnot necessitate the elimination of allwater, they are commercially available very widely and i atcomparatively reasonable cost. Ordinary alcohol for instance, whichcarries about five per cent. of water, but which however tends to raisethe fiber of wood if applied as a solvent base, may in accordance withthe present invention be so controlled as to avoid fiber-raising action,and operate with the highly desirable water-soluble type of dyes. Inorder to use water-soluble dyes, it is necessary to get them intosolution, as they are at best only slightly soluble in alcohol. Theglycols and glycerol are fairly good solvents for these dyes, but theiruse presents a serious difiiculty. About seven to ten per cent. of thesematerials is needed to keep the alcohol from 'raising the grain of thewood, and when this much is used, a greasy residue is left on the woodwhich is hygroscopic and picks up water thus in turn tending to raisethe fiber of the wood. The others of glycerol and of the higher glycolspresent the same difliculty. We have however discovered that in suchcombinations, a desirable control maybe had by incorporating a miscibleanhydrous solvent which evaporates more slowly than the alcohol, andfiber-raising may be prevented. The ethers of ethylene glycol aredesirable in thi's'connection. The ethylene glycol others may be usedwith ethyl alcohol or methanol; but we prefer to add two to five percent, of one of the higher ethers, or of glycol, in order to furtherincrease the solubility of the dyes in the final material. In general,the ethylene glycol ethers may be employed in amounts of ployed. Organicsolvents which are not anhyten to forty per cent. Alcohol, ethyl ormethyl,

Parts by weight 4 This is an excellent composition'in operation,

Water soluble dye I Glycol- Methyl ether of ethylene glycol Alcohol---Deep shades can be obtained with this solution. At very high humiditieshowever, its uses may occasion some tendency to fiber raising.

III. A mixture of ,Parts by weight Dye 4 Ether of ethylene glycol 4Alcohol 6 gives a good material for general usage, being characterizedby good solvent power and resistance to humidity in fiber-raising. As asolvent, this can also be desirably used to reduce or lighten this typeof stain, with very satisfactory results.

Other modes ofapplying the principle of the invention may be employed,change being made as regards the details described, provided theingredients stated in the following claim, or the equivalent of such, beemployed.

We therefore particularly point out and distinctly claim as ourinvention: a

A wood stain, which consists of about 4 parts of a water-soluble dye,about 5 parts of ethyl ether of diethylene glycol, about parts ofalcohol, and about 15 parts of methyl ether of ethylene glycol, all byweight.

' CHARLES G. MOORE.

MILTON ZUCKER.

